Where you’ll be stationed in the military is determined by a mix of the needs of the service and, to varying degrees depending on branch and career field, your own input. Each branch has some version of an assignments or “detailing” process, where a career counselor or detailer matches available billets to a service member’s job specialty, rank, and career timeline, while also weighing personal preferences service members submit for future assignments.
Needs of the service generally come first — a critically short-staffed unit or specialty will often take priority over an individual’s preference — but most branches do allow service members to submit a ranked list of preferred locations, and many detailers try to accommodate them where possible, especially later in a career when a service member has more history and more say.
Certain job specialties are tied to specific bases or ship homeports by nature of their equipment or mission, which narrows the realistic range of possible locations regardless of preference. Family circumstances, including programs some branches offer for married military couples or dependents with special medical needs, can also factor into assignment decisions.
If station location matters a great deal to you, talking directly with a detailer or career counselor early, and understanding how your specific specialty is typically assigned, is more useful than general assumptions about the process.